Accessibility in Blazor ListBox Component
25 Mar 20244 minutes to read
The Blazor ListBox component followed the accessibility guidelines and standards, including ADA, Section 508, WCAG 2.2 standards, and WCAG roles that are commonly used to evaluate accessibility.
The accessibility compliance for the Blazor ListBox component is outlined below.
| Accessibility Criteria | Compatibility |
|---|---|
| WCAG 2.2 Support |  |
| Section 508 Support | |
| Screen Reader Support | |
| Right-To-Left Support | |
| Color Contrast | |
| Mobile Device Support | |
| Keyboard Navigation Support | |
| Axe-core Accessibility Validation | |
- All features of the component meet the requirement.
- Some features of the component do not meet the requirement.
- The component does not meet the requirement.WAI-ARIA attributes
The Blazor ListBox component followed the WAI-ARIA patterns to meet the accessibility. The following ARIA attributes are used in the Blazor ListBox component:
| Attributes | Purpose |
|---|---|
role |
Indicates the ListBox component wrapper element as listbox, the UL element as presentation, and its list item as option. |
aria-label |
Provides an accessible name for the ListBox component. |
aria-multiselectable |
Applied to the element with the ListBox role, tells assistive technologies that the list supports multiple selection. The default value is true. |
aria-selected |
Applied to elements with role option that are visually styled as selected to inform assistive technologies that the options are selected. |
Keyboard interaction
The Blazor ListBox component followed the keyboard interaction guideline, making it easy for people who use assistive technologies (AT) and those who completely rely on keyboard navigation. The following keyboard shortcuts are supported by the Blazor ListBox component.
| Press | To do this |
|---|---|
| Up arrow | Moves focus to the previous option. |
| Down arrow | Moves focus to the next option. |
| Home | Moves focus to first option. |
| End | Moves focus to last option. |
| Space | Changes the selection state of the focused option. |
| Ctrl + A | Selects all options in the list. |
| Ctrl + Shift + Home | Selects the focused option and all options up to the first option. |
| Ctrl + Shift + End | Selects the focused option and all options down to the last option. |
| Ctrl + (Up or Down) | Press Ctrl key with up / down arrow or mouse to select multiple items. |
Ensuring accessibility
The Blazor ListBox component’s accessibility levels are ensured through an axe-core with playwright tests.
The accessibility compliance of the Blazor ListBox component is shown in the following sample. Open the sample in a new window to evaluate the accessibility of the Blazor ListBox component with accessibility tools.